Improvement in the manufacture of illuminating-gas



UNrTnn STATES PATENT Grauen.

GEORGE A. MCILHENNY, OF WASHINGTON, DISTRICT4 OF COLUMBIA.

Specification forming part of Letters Patent No. 65,927, dated June 18, 1867.

To all whom t may concern.-

Be it known that I, G. A. MCILHENNY, of Washington, in the county of Washington and District of Columbia, have invented certain new and useful Improvements in the Manufacture of Illuminating-Gas; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing making part of this specification a-nd to the letters of reference marked thereon, like letters indicatin like parts Wherever they occur.

To enable others skilled in the'art to construct and use my invention, I will proceed to describe it. y

My invention consists in preventing the -formation of carbon in the remtorts in the process of manufacturing illuminating-gas.

Figure l represents a front elevation of a bench of retorts and the hydraulic main as used in the manufacture of gas frm coals. Fig. 2 is a longitudinal vertical section; Fig. 3, a transverse vertical section.

In the manufacture of illuminating-gas from coal great difficulty has arisen from the forniation and deposit oi' carbon in the retorts. The formation of this material in the retorts is objectionable for these reasons: First, because, as it adheres with great tenacity to the walls of the retort, it is removed only with great difeulty, and at the expenditure of much time and labor, thereby delaying the operations of the factory and increasing the expense; second, by increasing the thickness oi' the Walls of the retort by its constant accumulation thereon, it decreases the capacity of the retort, and at the same time requires the use of more fuel to heat the contents of the retort because of the increased thickness of the Walls; and iinally, because, by the formation of carbon in the retort, the gas is deprived of a large percentage oi'theilluminating properties that it would otherwise possess. To remedy these difficulties is the' object of my invention, which conissts in relieving the retorts of the pressure caused by the sealing of the mouths of the tubes in the hydraulic main.

To accomplish this result I arrange a series of retorts, It, in the usual manner, and connect them by tubes @With the hydraulic main B, the ends of the said tubes entering the main on its upper side and extending about halfway to its bottom, as shown in Figs. 2 and 3. It is customary to iill the main With Water through a supply-pipe, as represented by h, Fig. 3, high enough to cover or seal the open ends or mouths ot' the tubes ic, the water, and coal-tar i'Which iioats thereon, rising in the main to a point indicated by the line e of Fig. 2, thus immersing the ends of the tubes leading from the retort. At that level a pipe, a, is connected' to the main B for the coal-tar to pass 0E through, by which the contents of the hydraulic main are maintained constantly at the level indicated by the line e. It is obvious that when thus arranged the gas which iiows from the retort through pipes c must displace the Water and tar which thus cover or sea-l77 their mouths, in order to enter the main, and as this necessarily requires considerable pressure, it follows that the-contents ofthe retort must at all times during the roasting process be subjected to this pressure. Now I have found by experiment that if this pressure can beremoved during the roasting process, then no carbon, or but very little, if any, will be deposited in the retorts. As the simplest means of doing this, and at the same time to retain the means of sealing the mouths of the pipes c to prevent the back liow ofn the gas when the retorts are opened for emptying and rechargiulg them, I apply to the main another escape-pipe, b, at a lower level than the ordinary pipe a. These pipes a and bare each provided with a cock or valve, so that either may be closed or opened at Will; and by opening the valve in the pipe -b and permitting the tar or tar and Water' to iioW through it I can at any time reduce the contents oi the main to the le vel oi' the line j, thereby unsealing the mouths of the pipes c and of course permitting the gas to flow from the retorts, as fast as formed, into the main B, thus relieving the retorts ofthe pressure which usually exists in them, and thereby preventingtheformation and deposit of carbon therein. It is obvious that valves might be arranged to close the mouths of the pipes c when the retorts are to be opened, said valves being opened when the retort is in operation; also that a valve might be arranged in the outletpipe E of the main, to be opened and closed at proper intervals; but such an arrangement would be neither as simple nor as efficient as the one herein described.

When the retorts are in operation the tar is allowed to pass oli' through the lower pipe I), but when it is desired to open the retorts for any purpose the eoek in pipe b is closed and that in pipe a is opened; the contents of the main in such ease being,` raised to a level with said pipe a, and thus sealing. or closing` the mouths 0l the pipes c, and thereby preventing the back ow or escape of any gas from the main.

By these simple means 1 prevent the formation of carbon in the retorts, and save much time, labor, and expense, and at the same time produce a richer gas at less expense.

Having thus described my invention, what I claim isl. The preventionof the deposit of Carbon Ain gas-retorts by the means described, or by any equivalent means.

@meer 2. I claim so arranging the pipes or tubes leading frein the retorts to the hydraulic main that the mouths of said pipes or tubes can be sealed or unsealed at pleasure.

l elairn providing the hydraulic main or a gas-factory with two or more pipes for the escape ofthe coal-tar7 when said pipes are arran ged at diierent heights and provided with cocks, so that the liquid contents of the main may be Inade to oeeupy a higher or lower level therein7 substantially as and for the pur pose set forth.

GEO. A. MCILHENNY.

Witnesses:

W. C. Denen, H. B. MUNN.

...nd-AU 

